Question

Well....a frog fell into a hole that was 14 ½ feet deep. He could jump 3 feet, but he slid back a foot each time he jumped. How many jumps does it take him to get out of the hole?

Answer 1

Each jump we advance three feet \(+3\) but slide back a foot \(-1\) so each jump gives us a net advancement of \(+2\). For an integer number \(n\) jumps, we have \(+2n\) and we want \(+2n\ge14\frac12\). Dividing both sides by two gives us \(n\ge 7\frac14\) hence the minimum whole number of jumps needed is \(8\).